RE: Aluminum tape

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Gary.Lau-at-compaq-dot-com>

When wrapping a toroid with aluminum tape, one can't just wrap a continuous
spiral.  It's difficult to explain unless you've tried it, but due to the
fact that the cylinder is curved, it would end up a mess.  Instead, one has
to use individual segments whose length is just over the minor
circumference.  These segments will just barely overlap at the O.D. and will
overlap a great deal at the I.D.

And you are quite correct that they are not ordinarily in good contact with
each other.  So rather than forming a helical inductor, they could
potentially be a collection of capacatively coupled elements.  There is
speculation that with the high voltages involved, that the insulating layer
may quickly break down.  On my toroids, I took precautions to ensure that
all of the tape segments were electrically joined.

Regards, Gary Lau
Waltham, MA USA

Original poster: "Oxandale, Terry by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <Toxandale-at-SPP-dot-org>


Please don't laugh when I ask pose this concern about Aluminum tape. It
seemed to me that if aluminum tape is wrapped around an object (such as
a toroid), that the end result would be a round helical winding of
aluminum tape, rather than a solid surface toroid. I reason this to be
because the sticky backing on the backside of the tape is
non-conductive. I overlaped two pieces tonight to verify this and found
that they had no conductance between the two of them. I eventually did
get a connection after rubbing the edges real hard, but this seemed to
me to be rather undesireable (inductance in your toroid???). But I see
folks using this stuff a lot.. Is this a non-issue that only I have a
concern about.

Terry (Un-Terry)